Be aware of your surroundings. It is untelling where these stolen explosives will turn up.

MARIETTA, Pa. — WGAL News 8 has learned that 30 to 40 Alcohol, Tobacco, Firearms and Explosives agents are in the Susquehanna Valley looking for hundreds of pounds of explosives that disappeared from a pipeline work site in Marietta, Lancaster County.

Thursday morning a helicopter circled the site as agents worked every possible angle. Agency officials say they are working with the Department of Homeland Security in case this involves terrorism. They are also checking the explosives black market, investigating whether the theft could have been an inside job and looking into whether this could have involved opponents of the pipeline. They say they are ruling nothing out.